My Father has 2 wives, 1st wife my mother died long ago left 3 sons, 1 daughter. 2nd wife my step-mother alive have 1 son, 7 daughters. How to distribute properties each one shares.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

You have not mentioned whether your mother died before or after your father; any way, if your father only left one or two wives and the children whom you mentioned in the question, then the inheritance should be divided as follows:

The share of the wife or the two wives is a one-eighth portion of inheritance, that is because of the existence of the children. So the two wives should share the one-eighth portion, but if he had only left one wife, then she would take by herself the one-eighth portion of inheritance. Allaah says (which means): {And for them [i.e. the wives] is one fourth if you leave no child. But if you leave a child, then for them is an eighth of what you leave.}[Quran 4:12]. The rest should be divided among the brothers and sisters, for the male a portion equal to that of two females', as Allaah says (which means): {Allaah instructs you concerning your children [i.e. their portions of inheritance]: for the male, what is equal to the share of two females.}[Quran 4:11].

Finally, it should be noted that if your mother died after the death of your father, then her share of inheritance from him should be divided among her heirs, as the Prophet said: "Whoever leaves any wealth [when he dies] it should be divided on his heirs." [Al-Bukhari and Muslim]  

Allaah knows best.